Building An Acoustic Guitar – Neck and Truss Rod

So, I’m continuing work on the guitar.  With the body essentially completed it’s time to focus on the neck.  So far I’ve got the neck cut out to rough shape and I’ve installed the truss rod.

Cutting the neck obandsawut was pretty simple.  I just used a template that I made from my plans to trace the shape on to my blank and then I cut it out at my band saw.

Once that was done I cut the joinery for the neck.  I used my domino with 14mm tenons for the job.  I really wanted to use a traditional dovetail neck joint for this but it just wasn’t working out or me.  I spent a week trying several different methods of cutting the joint with no success.  I guess there are some things you just can’t do without significant practice.  The other traditional way is a mortise and tenon joint.  So, if I was going to use a mortise and tenon I can’t see a reason why my domino wouldn’t do the job.  It does after all produce mortise aDominond tenon joinery.  This certainly isn’t a traditional method and I’ve never seen it done.  Perhaps I’m the first to attach a guitar neck with the Festool Domino.  With the joinery done it was time for a test fit!  It’s beginning to look like a guitar!



Test Fit

routingNext I needed to cut the groove for the truss rod to fit in.  This is when I realized I’d made my first mistake.  Luckily though it was something I could easily fix.  I should have cut the groove prior to cutting the neck to its rough shape.  Had I done this the blank would have been nice and square and it would have been easy to route a straight groove down the center of the neck blank.  Because I had already cut the neck out I had to attach it to a piece of 1/4″ plywood that was square with a straight edge.  y lining up the center line of the 1/4″ plywood and the center lin of my neck I was able to route the groove.  With the groove cut I needed to chisel out a spot on the headstock for the nut to be recessed in to.  This is the nut that makes the adjustments on the truss rod.

Once all of that was done I could make the truss rod itself.  I made it from a long piece of 3/16″ steel rod and 2 shorter pieces of 3/8″ steel rod.  The 3/16″ rod was cut to the length indicated in my plans for the truss rod.  I cut one piece of 3/8″ rod to 5/8″ long and the other to 1/2″ long.  The 5/8″ piece got a hole drilled through its side that I could insert the 3/16″ rod into.  I then welded these pieces together so the 3/16″ wouldn’t turn inside of the 3/8″ rod.  I then did a test fit of the rod in the neck.  When I did this I realized that I wasn’t able to get it back out.  I guess it fit really well.  So I had to make the rest of the truss rod while it was in the neck.

WeldingCutting threads

The next step was to thread the other end of the 3/16″ rod.  I used #10 32 tap and die set.  With the rod threaded I could then begin the make the nut.  I used the 1/2″ long piece of 3/8″ rod for the nut.  First I had to drill and ho

sawing nutle in the center of it for the tap and die set.  Next I cut the threads.  Finally I used a hacksaw to cut a groove on the side opposite the hole to fit a flat head screwdriver.  This is how I will be able to adjust the rod.  Finally I could install the rod in to the guitar neck.

With the rod in place I needed to cover its groove with an additional piece of wood.  As it turns out I had some of the material I cut for the binding on the guitar left over and it was a perfect fit.  So I cut it to length and glued it in.  I paid special attention not to get any glue on the truss rod itself because otherwise it may not function properly.


That’s as far as I’ve gotten on this crazy build so far.  Things seem to be going well.  Hopefully that continues.  Next up I’ll be working on the fretboard and shaping the neck!

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